getChildByName return null if publis setting is Flash 9

programming flash
1

Hi,

I am facing a weird problem.

The following code returns null if targeted player is Flash player 9 but works fine for Flash Player 10.

var _mc:MovieClip = getChildByName("introMC") as MovieClip;

It works fine if I give a delay using setTimeout.

I am not sure what I may be doing wrong. I have attached the source files. (Flash CS5 format)

Any help is appreciated